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This work considers using reduced basis techniques in connection to (smoothened) total variation regularization in electrical impedance tomography, but analogous ideas can also be used for other inverse elliptic boundary value problems. It…

Numerical Analysis · Mathematics 2026-02-18 A. Hannukainen , N. Hyvönen , V. Toresen

3D volumetric reconstruction from incomplete or noisy measurements is a fundamental problem in medical imaging and computational tomography. Deep image prior (DIP)-based methods have recently shown strong capability for solving inverse…

Computational Engineering, Finance, and Science · Computer Science 2026-05-29 Haijie Yuan , Chaoyan Huang , Srijita Bandopadhyay , Liyue Shen , Saiprasad Ravishankar

Diffusion-based sparse-view CT (SVCT) imaging has achieved remarkable advancements in recent years, thanks to its more stable generative capability. However, recovering reliable image content and visually consistent textures is still a…

Computer Vision and Pattern Recognition · Computer Science 2026-04-14 Tianqi Wang , Wenchao Du , Hongyu Yang

Iterative image reconstruction algorithms for optoacoustic tomography (OAT), also known as photoacoustic tomography, have the ability to improve image quality over analytic algorithms due to their ability to incorporate accurate models of…

Analysis of PDEs · Mathematics 2015-06-05 Kun wang , Richard Su , Alexander A. Oraevsky , Mark A. Anastasio

We study \emph{TV regularization}, a widely used technique for eliciting structured sparsity. In particular, we propose efficient algorithms for computing prox-operators for $\ell_p$-norm TV. The most important among these is $\ell_1$-norm…

Machine Learning · Statistics 2018-01-03 Álvaro Barbero , Suvrit Sra

Photon-counting computed tomography (PCCT) has emerged as a promising imaging technique, enabling spectral imaging and material decomposition (MD). However, images typically suffer from a low signal-to-noise ratio (SNR) due to constraints…

There are two de facto standard architectures in recent computer vision: Convolutional Neural Networks (CNNs) and Vision Transformers (ViTs). Strong inductive biases of convolutions help the model learn sample effectively, but such strong…

Computer Vision and Pattern Recognition · Computer Science 2022-10-05 Yunsung Lee , Gyuseong Lee , Kwangrok Ryoo , Hyojun Go , Jihye Park , Seungryong Kim

The art of recovering an image from damage in an undetectable form is known as inpainting. The manual work of inpainting is most often a very time consuming process. Due to digitalization of this technique, it is automatic and faster. In…

Computer Vision and Pattern Recognition · Computer Science 2013-07-15 S. Padmavathi , N. Archana , K. P. Soman

Two new optimization techniques based on projections onto convex space (POCS) framework for solving convex optimization problems are presented. The dimension of the minimization problem is lifted by one and sets corresponding to the cost…

Data Structures and Algorithms · Computer Science 2013-09-04 Mohammad Tofighi , Kivanc Kose , Ahmet Enis Cetin

Although sparse-view computed tomography (CT) has significantly reduced radiation dose, it also introduces severe artifacts which degrade the image quality. In recent years, deep learning-based methods for inverse problems have made…

Image and Video Processing · Electrical Eng. & Systems 2024-01-02 Shuo Xu , Yucheng Zhang , Gang Chen , Xincheng Xiang , Peng Cong , Yuewen Sun

Propagation-based X-ray phase-contrast imaging (PBI) enables high-contrast visualization of lung structures and holds strong medical potential. However, safe translation to the clinic will require a substantial radiation dose reduction,…

In the present work we present Training Noise Token (TNT) Pruning for vision transformers. Our method relaxes the discrete token dropping condition to continuous additive noise, providing smooth optimization in training, while retaining…

Computer Vision and Pattern Recognition · Computer Science 2025-03-17 Mingxing Rao , Bohan Jiang , Daniel Moyer

Total Variation (TV) is a popular regularization strategy that promotes piece-wise constant signals by constraining the $\ell_1$-norm of the first order derivative of the estimated signal. The resulting optimization problem is usually…

Optimization and Control · Mathematics 2020-10-20 Hamza Cherkaoui , Jeremias Sulam , Thomas Moreau

In this work, a novel algorithm called SVM with Shape-adaptive Reconstruction and Smoothed Total Variation (SaR-SVM-STV) is introduced to classify hyperspectral images, which makes full use of spatial and spectral information. The…

Computer Vision and Pattern Recognition · Computer Science 2022-04-15 Ruoning Li , Kangning Cui , Raymond H. Chan , Robert J. Plemmons

Many modern iterative solvers for large-scale tomographic reconstruction incur two major computational costs per iteration: expensive forward/adjoint projections to update the data fidelity term and costly proximal computations for the…

Optimization and Control · Mathematics 2026-02-11 Evangelos Papoutsellis , Zeljko Kereta , Kostas Papafitsoros

Vision Transformer (ViT) has demonstrated promising performance in computer vision tasks, comparable to state-of-the-art neural networks. Yet, this new type of deep neural network architecture is vulnerable to adversarial attacks limiting…

Computer Vision and Pattern Recognition · Computer Science 2023-11-02 Shashank Kotyan , Danilo Vasconcellos Vargas

We propose a new type of regularization functional for images called oscillation total generalized variation (TGV) which can represent structured textures with oscillatory character in a specified direction and scale. The infimal…

Numerical Analysis · Mathematics 2018-09-17 Yiming Gao , Kristian Bredies

Denoising is of utmost importance for the visualization and processing of images featuring low signal-to-noise ratio. Total variation methods are among the most popular techniques to perform this task improving the signal-to-noise ratio…

Signal Processing · Electrical Eng. & Systems 2022-01-24 Gonzalo D. Maso Talou , Pablo J. Blanco

Proton therapy is a modality in fast development. Characterized by a maximum dose deposition at the end of the proton trajectory followed by a sharp fall-off, proton beams can deliver a highly conformal dose to the tumor while sparing…

Medical Physics · Physics 2022-05-18 François Smekens , Nicolas Freud , Bruno Sixou , Guillaume Beslon , Jean M Létang

The development of computed tomography (CT) image reconstruction methods that significantly reduce patient radiation exposure while maintaining high image quality is an important area of research in low-dose CT (LDCT) imaging. We propose a…

Machine Learning · Statistics 2019-06-14 Xuehang Zheng , Saiprasad Ravishankar , Yong Long , Jeffrey A. Fessler